This invention relates to fluid dispensing devices in which constituents of the fluid mixture can be maintained in separate chambers and in which the separated constituents can be mixed in vitro, when desired, by placing the chambers in communication with one another. A dislodeable stopper serves to maintain separation of mixture components in the two chambers, which can be dislodged by a plunger within one chamber which is activated by the depression of the flexible walls of one of the chambers.
Container devices having multiple compartments for separately enclosed materials to be mixed prior to use are described in U.S. Pat. Nos. 3,340,873, 3,354,883, 3,397,694, 3,411,503, 4,331,146, 4,412,836, and 4,330,531, having a thin diaphragm type membrane separating the two compartments. These systems are not considered entirely reliable because of inability to maintain a fluid-tight seal between the compartments. U.S. Pat. No. 3,464,414 discloses a rigid walled two chambered mixing vial utilizing hydraulic pressure to dislodge a plug member between the two chambers.